Multicomponent Metallo-Supramolecular Nanocapsules Assembled from Calix[4]resorcinarene-Based Terpyridine Ligands

Tetrafunctionalized calix[4]resorcinarene cavitands commonly serve as supramolecular scaffolds for construction of coordination-driven self-assembled capsules. However, due to the calix-like shape, the structural diversity of assemblies is mostly restricted to dimeric and hexameric capsules. Previously, we reported a spontaneous heteroleptic complexation strategy based on a pair of self-recognizable terpyridine-based ligands and Cd^II ions. Building on this complementary ligand pairing system, herein three types of nanocapsules, including a dimeric capsule, a Sierpiński triangular prism, and a cubic star, could be readily obtained through dynamic complexation reactions between a tetratopic cavitand-based ligand and various multitopic counterparts in the presence of Cd^II ions. The dimeric capsular assemblies display the spacer-length-dependent self-sorting behavior in a four-component system. Moreover, the precise multicomponent self-assembly of a Sierpiński triangular prism and a cubic star possessing three and six cavitand-based motifs, respectively, demonstrates that such self-assembly methodology is able to efficiently enhance architectural complexity for calix[4]resorcinarene-containing metallo-supramolecules.